The present invention relates to a method and an apparatus for manufacturing a magnetic recording medium, and more particularly to a method and an apparatus for manufacturing a magnetic recording medium capable of stabilizing accuracy of the width of a magnetic recording medium cut to have a given width.
Hitherto, magnetic recording mediums, such as audio tapes, video tapes and computer tapes, have been manufactured such that a wide width blank web comprising a non-magnetic support member on which a magnetic layer containing ferromagnetic particles is formed, is conveyed by rollers. Then, the web is subjected to an orienting process, a drying and solidifying process and surface treatment. Finally, the web is cut into the longitudinal direction of the web.
After the magnetic layer of the wide web is subjected to surface treatment, the web is temporarily wound up. Then, the wound web is set to a cutting apparatus. FIG. 3 shows a state in which the web has been set to the cutting apparatus. In the cutting apparatus 20, the blank web 50 is fed from a feeding roller 100 to be conveyed on a conveying roller 21, and then guided to a cutting blade 40 through a reference roller 22 and conveying rollers 23, 24 and 25.
The web 50 guided to the cutting blade 40 is cut into the longitudinal direction by upper and lower blades 41 and 42 which constitute the cutting blade 40. Thus, a plurality of magnetic recording mediums 51 each having a small width are formed. The magnetic recording mediums 51 are conveyed on the conveying rollers 27 and 28 to be wound around individual winding rollers 29.
A wide web having a width of, for example, about 1000 mm has a thick coating in the central portion thereof so as to reliably be wound up by utilizing its tension. If the web having the above-mentioned coating is kept maintained in a state that it has been wound around the feeding roller for a predetermined period of time, the web is apt to be slack easily due to the fact that the central portion X is stretched excessively as shown in FIG. 4. Such web kept maintained under the above-mentioned state for the time is sequentially fed from the feeding roller, subjected to the foregoing processes, and then moved to the cutting portion 40 to be cut into predetermined number of parts (for example, six parts in FIG. 4) At that time, a portion of the web where must be cut is undesirably moved vertically and laterally by the existence of the slack at the central portion X thereof. Accordingly, it is difficult to obtain a plurality of cut webs (that is, six parts) which have the same widths Y one another. Namely, the plurality of cut webs each having stable width cannot be realized by the cutting.
Note that a thick web having a large thickness does not arise a critical problem because the thick web is free from considerable slack of the central portion, whereas a thin web, such as a thin metal web, having a small thickness suffers from the problem of the slack of the central portion.